//
// Created by ✎﹏ℳ๓独赏 ☆独醉 on 2023/4/14.
//
#include <stdio.h>
int main(){
    int arr[10]={1,2,3,4,5,6,7,8,9,10},x;
    int left=0,right=sizeof(arr)/sizeof(int)-1,mid=0;
    scanf("%d",&x);
    while(left<=right){
        mid =(left+right)/2;
        if(x>arr[mid])left=mid+1;
        else if(x<arr[mid])right=mid-1;
        else{printf("%d",mid);break;}
    }
    if(left>right){
        printf("Not Found");
    }
    return 0;
}